M S Bronzini

A specialized equilibrium assignment algorithm for air quality modeling

Abstract A multiple user class equilibrium assignment algorithm is formulated to determine vehicle trips and the vehicle miles of travel (VMT) in various operating modes on highway links. A heuristic solution algorithm based on the Frank–Wolfe decomposition of the equilibrium assignment problem is presented. The treatment of intrazonal trips, which are very important for emission studies is also discussed. The solution algorithm is implemented in a traffic assignment program for emission studies, referred to as TAPES. The use of the algorithm is demonstrated through a TAPES model case study on a Charlotte, NC network database for 1990 AM peak period. The operating mode mix of VMT in cold transient, hot transient and hot stabilized modes, also known as the mix of cold-starts, hot-starts and stabilized mode trips, is derived on a link by link basis. The results are aggregated by facility type and the location of link segments. It is observed that the operating mode fractions in transient and stabilized modes could vary widely across different facility types geographic locations. The aggregated operating mode fractions derived from the assignment analysis indicates that a lesser proportion of VMT operates in cold and hot transient modes when compared to the operating mode mix derived from the Federal Test Procedure (FTP).

The Rail Carrier-Route Choice Model

Abstract There is currently considerable interest in studying the behavior of both shippers and carriers in the transportation market place. The Rail Carrier-Route Choice Model, or (RC)2, was developed to model the behavior of carriers in the rail industry. The (RC)2 routes individual shipments, one at a time, through a network representation of the U.S. rail system. The algorithm used by the model finds the path for each shipment which minimizes each railroads operating (fully allocated) cost while maximizing the railroads share of total revenue. It does this by finding a sequence of intercarrier transfer nodes which minimizes the railroads cost to provide service between the nodes and which also minimizes the amount of available revenue that is “lost” to other railroads. The (RC)2 has been tested for several known and anticipated coal shipments for various electric utilities. Results of test runs are presented and show the model to be computationally efficient and an accurate selector of routes.

A transportation-sensitive model of a regional economy☆

Abstract An integrated model system for analyzing alternative regional multimodal freight transportation infrastructures is developed. An econometric model uses transportation price information to determine the origin-destination flows of commodities throughout a region. These flows are input to a freight modal split model, which apportions them among the various modes on the bases of relative transport service variables. A network simulation model assigns the commodity flows by mode to specific routes and calculates flow-dependent origin-destination impedance values. Equilibrium values of model outputs are attained by means of a multi-feedback iteration process. The nature of model system interactions is explored by applying the model to a hypothetical region.

OHIO RIVER NAVIGATION INVESTMENT MODEL: REQUIREMENTS AND MODEL DESIGN

Oak Ridge National Laboratory is assisting the U.S. Army Corps of Engineers in improving its economic analysis procedures for evaluation of inland waterway investment projects along the Ohio River system. The context and design of an integrated approach to calculating the systemwide benefits from alternative combinations of lock and channel improvements, providing an ability to project the cost savings from proposed waterway improvements in capacity and reliability for up to 50 years into the future, is described. The design contains an in-depth treatment of the levels of risk and uncertainty associated with different multiyear lock and channel improvement plans, including the uncertainty that results from a high degree of interaction between the many different waterway system components.

Developing a toolkit for hazardous materials transportation education

The objective of this project was to develop model postsecondary education curricula that would address the knowledge, skills, and abilities needed for the safe, secure, and efficient transportation of hazardous materials (hazmat). More than 170 existing hazmat-related education and training programs and other resources offered by industry and government were identified and evaluated to assess the state of the art and to locate materials that might be used in the model curricula. Stakeholder groups that would benefit from hazmat transportation education were identified and defined, and draft materials were developed around a set of topics to meet stakeholder needs. The draft curricula were reviewed at a peer exchange workshop involving approximately 50 stakeholders representing various interests in hazmat transportation. The final model curricula, presented in the form of a toolkit that can be adapted for various audiences and educational purposes, consist of PowerPoint presentations and supporting materials covering eight topics: introduction to hazmat transportation, hazmat logistics, legal and regulatory environment, mode and route selection, risk management, hazmat transportation incident management, security of hazmat transportation shipments, and workforce development issues. The paper considered barriers to implementation of the model curricula and proposed follow-up activities to help overcome them.

Model Education Curricula and Toolkit for the Transportation of Hazardous Materials

The objective of this project was to develop model post-secondary education curricula that address the knowledge, skills, and abilities needed for the safe, secure, and efficient transportation of hazardous materials (hazmat). Over 170 existing hazmat-related education and training programs and other resources offered by industry and government were identified and evaluated, to assess the state of the art and to locate materials that might be used in the model curricula. Stakeholder groups who would benefit from hazmat transportation education were identified and defined, and draft materials were developed around a set of topics to meet stakeholder needs. The draft curricula were reviewed at a peer exchange workshop involving approximately fifty stakeholders, representing various interests in hazmat transportation. The final model curricula, presented in the form of a toolkit that can be adapted for different audiences and educational purposes, consist of PowerPoint presentations and supporting materials covering eight topics: introduction to hazmat transportation; hazmat logistics; legal and regulatory environment; mode and route selection; risk management; hazmat transportation incident management; security of hazmat transportation shipments; and workforce development issues. The report considers barriers to implementation of the model curricula, and proposes follow-up activities to help overcome them.

Inland Waterways: Still or Turbulent Waters Ahead?

Waterway transportation has played an important role in the history of the United States, and it continues to be important today. The federal government is responsible for building and maintaining the locks and channels that provide navigation, with funding coming partly from general revenues and partly from the fuel tax revenues deposited in the Inland Waterways Trust Fund. A current concern is that nearly half of the lock chambers in the system are over fifty years old, so the backlog of structures requiring major rehabilitation or replacement is large and growing. Expenditures from the trust fund at a rate sufficient to meet this need would deplete the fund in a matter of a few years. Other current policy issues include continued operation of tributary waterways with low traffic, continued subsidy of the water mode in the face of federal budget deficit reduction efforts, environmental effects of tow traffic, and disposal and beneficial reuse of dredged material.